1. Field of the Invention
The present invention relates to closures for chambers and, in particular, to a chamber door which may be vertically displaced relative to the door frame as well as undergo rotational movement.
2. Description of the Invention Background
Various forms of door-like closures for openings in and surrounded by a frame are known. In many types of doors, the door is mounted for rotational or swinging movement relative to a door frame by means of a hinge. Most often, the door is only configured to rotate or swing relative to a door frame and no other door movements are possible.
However, in some instances, it is expedient that a door be capable of movements in addition to swinging relative to the door frame. For example, in certain environments, a door of a pressurizable chamber, such as a sterilization apparatus, must be movable between an open position in which access to the chamber is permitted, an intermediate position in which access to the chamber is prohibited but in which the door is not in complete alignment with the door frame of the chamber, a confronting position in which the door is vertically lowered relative to the door frame so that the door is in facing relation thereto and a sealed position in which the door is moved horizontally toward the door frame to effect the sealing of the chamber by the door's seal. In such an apparatus, the door must be capable of rotational movement between the open and the intermediate positions, vertical displacement between the intermediate and confronting positions and horizontal displacement between the confronting and sealed positions. Previous means for vertically displacing a door have proven problematic. For example, in some systems, the door is manually lifted by an operator. While this approach may be suitable for small, wall-mounted chambers, it will be readily appreciated that such a structure is completely unworkable with large chambers mounted at floor level. A previous device for lifting the door of a floor-level chamber includes a pivotally mounted hydraulic cylinder for lifting the door above the floor of the room in which the chamber is located. Such a device requires the provision of a complicated hydraulic system which is initially expensive and is costly to maintain and operate. In addition, if the door is to undergo such rotational, vertical and horizontal movements, the door supporting structure must allow such manipulations. Heretofore, no hinge has proven satisfactory to allow the rotational, vertical and horizontal movement of a door of a pressurizable vessel such as a sterilization apparatus.
The subject invention is directed toward a door which overcomes, among others, the above-discussed problems and which is straightforward in design, installation and operation and which is allowed to rotate, be vertically displaced and horizontally displaced relative to a door frame.